Ink fountain having a continuous metering bar with zonal adjustment

ABSTRACT

An ink fountain having a metering bar in the form of a continuous strip of tough resilient material, the bar being recessed in a slot formed in the frame with only its presented edge exposed and abutting the fountain roller. The metering bar is adjusted by a series of adjusting mechanisms with respective grippers uniformly spaced along the rear edge of the strip to define zones of adjustment, with the rear edge of the strip being deeply relieved between the adjacent grippers to form intermediate regions of reduced cross section so as to provide localied flexibility to permit relative independent zonal movement of the adjusting mechanisms for localized metering of the ink film. In the disclosed embodiment each gripper has a plunger which is reciprocated through a narrow range by a motor driven cam and cam follower, each plunger having provision for length adjustment and each plunger having a return spring to maintain the cam follower seated on the cam.

United States Patent Cappel et al.

INK FOUNTAIN HAVING A CONTINUOUS METERING BAR WITH ZONAL ADJUSTMENTAssignee:

Filed:

Appl. No; 551,630

Inventors: Bert Cappel, Offenbach-Bieber;

Siegfried Schuhmann, Offenbach; Klaus Wolf, Neu-lsenburg, all of GermanyRoland Offsetmaschinentabrik Faber & Schleicher AG, Germany Feb. 21,1975 Related US. Application Data Oct. 21, 1975 Primary Examiner-14 ReedFisher Attorney, Agenl, 0r FirmWolfe, Hubbard, Leydig, Voit & Osann, Ltd

[57] ABSTRACT An ink fountain having a metering bar in the form of acontinuous strip of tough resilient material, the bar being recessed ina slot formed in the frame with only its presented edge exposed andabutting the fountain roller. The metering bar is adjusted by a seriesof ad justing mechanisms with respective grippers uniformly spaced alongthe rear edge of the strip to define zones of adjustment, with the rearedge of the strip being deeply relieved between the adjacent grippers toforrr intermediate regions of reduced cross section so as It providelocalied flexibility to permit relative indepen dent zonal movement ofthe adjusting mechanisms fox localized metering of the ink film. In thedisclosed em bodiment each gripper has a plunger which is recipro catedthrough a narrow range by a motor driven can and cam follower, eachplunger having provision foi length adjustment and each plunger having areturr spring to maintain the cam follower seated on the cam.

10 Claims, 3 Drawing Figures US. Patent Oct. 21, 1975 3,913,479

INK FOUNTAIN HAVING A CONTINUOUS METERING BAR WITH ZONAL ADJUSTMENT Thisapplication is a continuation-in-part of our US. application, Ser. No.371,594, filed On June 20, 1973.

It is an object of the present invention to provide an ink fountainwhich employs an ink metering bar in the form of a continuous strip oftough flexible material in abutting relation to the fountain roller, thestrip being provided with a series of grippers with relief betweenadjacent grippers to define adjustable sections separate by intermediateregions of localized flexibility, and with each of the adjustablesections having an adjusting mechanism to provide an ink film which iscontinuous along the fountain roller but which enables accurate andindependent metering of film thickness in closely spaced zones ofadjustment.

It is a further object to provide an ink fountain which permits columnby column adjustment of ink flow by means of independently adjustablesections but which avoids the leakage problems generally associated withsectional adjustment.

It is a related object to provide an ink fountain having a meteringstrip for metering a film of ink which is continuous along the length ofthe fountain roller but which is subject to a wide variation inadjustment between adjacent zonal sections thereby to permit widevariations in the rate at which ink is furnished to adjacent columnpositions on the printed sheet.

lt is another object of the present invention to provide a sectionedmetering bar having a presented edge of which only the presented edgeportion is in contact with the ink and which avoids slideability betweenthe sections so that each of the sections of the bar may be adjustedreliably using relatively low adjusting forces in spite of accumulationof dried or gummy ink.

It is yet another object of the invention to provide a metering type inkfountain which may be inexpensively constructed, which includes aplurality of adjusting mechanisms having individual adjusting motors oflow power capability, and which is capable of operating for long periodssubstantially free of maintenance problems.

Other objects and advantages of the invention will become apparent uponreading the attached detailed description and upon reference to thedrawings in which:

FIG. 1 is a vertical section taken through an ink fountain embodying thepresent invention.

FIG. 2 is a fragmentary plan view of the metering bar used in thestructure of FIG. I and looking along the line 2-2 therein.

FIG. 3 is a fragmentary perspective showing a typical adjusting linkageused in the device of FIG. 1.

While the invention has been described in connection with a preferredembodiment, it will be understood that we do not intend to be limited tothe particular embodiment shown but intend, on the contrary, to coverthe various alternative and equivalent forms of the invention includedwithin the spirit and scope of the appended claims.

Turning now to FIG. I there is shown an ink fountain having a frame 70which includes an upper trough portion 71 and a lower, or base, portion72. The portions are hinged together for relative movement about a hingeaxis 73. The two portions, together, define a horizontal slot 74. Fittedsnugly in the slot is a metering bar having a presented edge, or tip, 76which abuts against the surface 77 of a fountain roller 78, the plane ofthe metering bar preferably falling close to the axis 79 of the roller.

The trough portion 71 includes a body of ink indicated at 1. When thefountain roller is rotated in the direction shown, so that the surface77 passes downwardly through the body of ink, a film of ink isestablished on the fountain roller which depends upon the clearancebetween the metering bar and the roller surface.

In accordance with the present invention the metering bar 75 is in theform of a continuous strip of tough resilient material having parallelside walls snugly fitted in the horizontal slot and with a plurality ofadjusting mechanisms, including respective grippers uniformly spacedalong the rear edge of the strip to establish adjustable sectionsdefining a series of zones of adjustment, the rear edge of the stripbeing deeply relieved between adjacent grippers to form intermediateregions of reduced cross section with the resulting flexibilitypermitting independent relative movement of the adjusting mechanisms andlocalized control of the ink film in the respective zones.

Turning to FIGS. 2 and 3, the metering bar 75 consists of spacedadjustable sections 80, preferably corresponding to column positions,with relief between the sections in the form of notches 81 definingnarrow bridges of resilient material as indicated at 82 between theadjustable sections. The metering bar is of generally rectangular crosssection presenting a flat upper face 85 and a flat lower face 86parallel thereto which engage the upper and lower walls of the slot 74in the frame structure. To provide additional insurance against leakageof ink along the metering bar, the walls of the frame members arelongitudinally relieved to form opposed grooves which are occupied bystrips of resilient sealing material indicated at 87, 88.

The notches 81 are relatively narrow compared to the adjustable sections80 and are quite deep, penetrating into the strip a distance which isthe major portion of the width of the strip. The roots of the notchesare of smoothly arcuate profile so that the bridges 82 of reduced crosssection produce a gradual transition from one adjustable section to thenext so that the sections may be differentially adjusted with avoidanceof any sharply defined shear plane, or region of concentrated stress,between them.

For the purpose of moving each of the sections 80 toward and away fromthe fountain roller to adjust the film thickness, a connecting linkage90 is provided having a gripper 91 of C" cross section having lips registering with longitudinal grooves formed on the upper and lower surfacesof the strip. Each gripper is permanently secured to a plunger 92 whichis screwed into a bushing 93. Screwed into the opposite end of thebushing, with a differential or opposite thread, is a plunger portion 94connected to a clevis 95. The clevis has a pin 96 which mounts ananti-friction bearing 97, the surface of the bearing serving as a camfollower surface 98.

For positioning the cam follower surface, a cam 100 is provided having aslightly eccentric surface, the cam being mounted upon a drive shaft 101connected to a gear box 102 driven by a remotely controlled, reversible,electric drive motor 103. For maintaining the cam follower surfacesolidly bottomed, at all times, against the surface of the cam 100, astrong return, or biasing, spring is provided which is preferably in theform of a stack of cupped spring (Bellville) washers S interposedbetween the bushing 93 and the frame.

It will be apparent, then, that when the high of the cam is crowdedagainst the cam follower surface 98, the linkage 90 is translatedoutwardly, advancing the associated section 80 of the metering bartoward the fountain roller to reduce the film thickness. When the cam isrotated by the motor to its low position, the spring washers 105 arefree to expand causing the section of the metering bar to be retractedfrom the fountain roller to increase the film thickness. This process isrepeated for each column position for metering of the ink in accordancewith the amount required in each column position. For the purpose ofestablishing a reference condition for all of a plurality of linkages90, the plungers 94 may be screwed in and out of the bushings which theyengage and with the adjusted position being preserved by a set screw orthe like in each bushing.

It will also be apparent that while it is preferred to employ individualadjusting motors 103 to effect zonal adjustment of the ink film, theinvention is not limited thereto and the cams 100 may be provided, ifdesired, with manual adjusting means and with scales calibrated in termsof film thickness to achieve reproducible settings.

The invention is not limited to use of any particular tough resilientmaterial for the metering bar 75. Many different plastics and syntheticrubbers are selectively available having a durometer rating between70(A) and 90(D) and which combine the features of toughness,flexibility, and dimensional stability in the presence of the variousinks and solvents which may be used in a practical press and havingcharacteristics which remain instant in spite of the passage of time.The plastic material which is sold by the Bayer organi' zation under thetrademark VOLKOLLAN is, however, preferred.

Only a very narrow tip portion of the strip is exposed, namely, thatportion immediately adjacent the presented edge 76 so that there islittle or no accumulation ofdried or gummy ink. Since the sections areresiliently joined, the cementing of adjacent sections, which tends tooccur when separate relatively slideable sections are employed, cannotoccur. Because of the positive push-pull operation of the gripper 90,combined with the high degree of mechanical advantage of the cam,precise and consistent setting is assured using only low power motors.The power requirement is further reduced by the fact that the meteringstrip is of limited width dimension, and deeply notched, so that only alimited area is in contact within the slot 74 to produce a snug fit andeffective seal against leakage while nevertheless reducing thefrictional forces which must be overcome when making an adjustment.

lt will be apparent that the above described embodiment amply carriesout the objects of the invention providing a structure which enableszonal metering of ink with smooth transition of ink thickness betweenzones, which may be adjusted with a high degree of precision andreproducibility, which is capable of operating over long periods of timewithout maintenance or readjustment and which is inherently economicalfor use on new presses as well as use, for replacement purposes, onpresses which are already in the field. The term gripper as used hereinis a general term covering any means providing localized connectionbetween a section of the strip and its associated adjusting means.

What is claimed is:

1. In an ink fountain the combination comprising a frame defining ahorizontal slot having parallel walls, a fountain roller rotatable inthe frame adjacent the slot, a metering bar mounted in the slot andhaving a presented edge arranged in abutting relation with the surfaceof the roller, the frame being shaped to support a body of ink adjacentthe metering bar so that a film of ink is formed on the roller by thebar as the roller is rotated, the metering bar being in the form of acontinuous strip of tough resilient material having parallel side wallssnugly fitted in the horizontal slot with only the presented edgeportion extending therefrom, a plurality of adjusting mechanismsincluding respective grippers uniformly spaced along the rear edge ofthe strip to establish adjustable sections defining a series of zones ofadjustment, the rear edge of the strip being deeply notched betweenadjacent grippers to form intermediate regions of reduced cross sectionso as to provide 10- calized flexibility to permit independent relativemovement of the adjusting mechanisms and localized metering of the inkfilm in the respective zones.

2. The combination as claimed in claim 1 in which each adjustingmechanism includes a plunger and cam follower, a rotatable cam foroperating on the cam follower, and a spring interposed between the frameand the plunger for maintaining the cam follower bottomed on the cam.

3. The combination as claimed in claim 1 in which each gripper has aplunger which extends rearwardly at right angles to the strip and inwhich each plunger has means including a cam and cam follower foradjusting the position of the gripper and the corresponding section ofthe strip with respect to the frame and fountain roller.

4. The combination as claimed in claim 1 in which the strip has flatparallel sides and in which each of the grippers is of "C" cross sectionfor gripping a corresponding portion of the rear edge of the strip.

5. The combination as claimed in claim 1 in which each mechanismincludes a plunger secured to the gripper, means including a motordriven cam and cam follower at the end of the plunger for positioningthe gripper and the corresponding portion of the strip with respect tothe fountain roller, and means for adjusting the effective length of theplunger to establish a reference condition.

6. The combination as claimed in claim I in which the regions of reducedcross section are of arcuate profile to provide smooth transitionbetween adjacent adjustable sections and are sufficiently flexible as toenable a large disparity in the adjustment of the adjacent sections freeof concentration of stress.

7. The combination as claimed in claim 1 in which the notches havesubstantially parallel sides with smoothly arcuate roots and are of adimension, longitudinally of the strip, which is only a minor fractionof the dimension of the adjustable sections.

8. The combination as claimed in claim 7 in which each notch extendsinwardly of the strip a distance which is the major portion of the widthof the strip.

9. The combination as claimed in claim 3 in which individual motors areprovided for individual zonal adjustment of the adjustable sections.

10. The combination as claimed in claim 1 in which the walls of the slotare longitudinally relieved to form opposed grooves and in which thegrooves thus formed are occupied by resilient sealing material, therebyto preclude leakage of ink between the metering strip and the walls ofthe slot.

i 4 i l

1. In an ink fountain the combination comprising a frame defining ahorizontal slot having parallel walls, a fountain roller rotatable inthe frame adjacent the slot, a metering bar mounted in the slot andhaving a presented edge arranged in abutting relation with the surfaceof the roller, the frame being shaped to support a body of ink adjacentthe metering bar so that a film of ink is formed on the roller by thebar as the roller is rotated, the metering bar being in the form of acontinuous strip of tough resilient material having parallel side wallssnugly fitted in the horizontal slot with only the presented edgeportion extending therefrom, a plurality of adjusting mechanismsincluding respective grippers uniformly spaced along the rear edge ofthe strip to establish adjustable sections defining a series of zones ofadjustment, the rear edge of the strip being deeply notched betweenadjacent grippers to form intermediate regions of reduced cross sectionso as to provide localized flexibility to permit independent relativemovement of the adjusting mechanisms and localized metering of the inkfilm in the respective zones.
 2. The combination as claimed in claim 1in which each adjusting mechanism includes a plunger and cam follower, arotatable cam for operating on the cam follower, and a spring interposedbetween the frame and the plunger for maintaining the cam followerbottomed on the cam.
 3. The combination as claimed in claim 1 in whicheach gripper has a plunger which extends rearwardly at right angles tothe strip and in which each plunger has means including a cam and camfollower for adjusting the position of the gripper and the correspondingsection of the strip with respect to the frame and fountain roller. 4.The combination as claimed in claim 1 in which the strip has flatparallel sides and in which each of the grippers is of ''''C'''' crosssection for gripping a corresponding portion of the rear edge of thestrip.
 5. The combination as claimed in claim 1 in which each mechanismincludes a plunger secured to the gripper, means including a motordriven cam and cam follower at the end of the plunger for positioningthe gripper and the corresponding portion of the strip with respect tothe fountain roller, and means for adjusting the effective length of theplunger to establish a reference condition.
 6. The combination asclaimed in claim 1 in which the regions of reduced cross section are ofarcuate profile to provide smooth transition between adjacent adjustablesections and are sufficiently flexible as to enable a large disparity inthe adjustment of the adjacent sections free of concentration of stress.7. The combination as claimed in claim 1 in which the notches havesubstantially parallel sides with smoothly arcuate roots and are of adimension, longitudinally of the strip, which is only a minor fractionof the dimension of the adjustable sections.
 8. The combination asclaimed in claim 7 in which each notch extends inwardly of the strip adistance which is the major portion of the width of the strip.
 9. Thecombination as claimed in claim 3 in which individual motors areprovided for individual zonal adjustment of the adjustable sections. 10.The combination as claimed in claim 1 in which the walls of the slot arelongitudinally relieved to form opposed grooves and in which the groovesthus formed are occupied by resilient sealing material, thereby topreclude leakage of ink between the metering strip and the walls of theslot.